Felt materials have been used commonly in industrial applications. They possess good dimensional stability. They can be made with a wide variety of natural or synthetic fibers to withstand the mechanical, chemical and thermal requirements required by the application.
Felts constructed with PTFE fibers possess superior chemical and thermal resistance and possess desirable mechanical properties, especially low coefficient of friction.
Some applications using PTFE felt require a seal across a pressure differential. The seal requires resistance to solid or liquid penetration of the felt. Current felts are too porous and will allow particulate, liquid and gases to penetrate.
The present invention attempts to retain the good physical, mechanical and chemical properties of PTFE felts while preventing penetration of liquids and solids through the felt.
One use of felt sealing materials is in a rotating perforated drum for separating solid particulate from a liquid which needs to be sealed at the drum edges in order to prevent solids or liquids from being drawn in the stationary drive areas.
This invention provides a novel material for sealing the area between such a rotating drum and the stationary drive housing.